1. Field of the Invention
This invention relates to traffic-rated covers for underground utility vaults and more specifically the structure used to bolt down and secure the hatch to the frame thereof, thereby holding the hatch closed on the frame with a semi-weather-tight connection with the frame and also holding the hatch stationary and stable as heavy vehicular and pedestrian traffic passes overtop.
2. Description of Related Art
A utility vault is an underground room providing access to subterranean public utility equipment, such as valves or other flow control devices for drinking water, drainage water, sewage, natural gas, or steam distribution networks, or switches, routers, or other electronic equipment for electric, telecommunications, television, or internet distribution networks. Utility vaults are similar to mechanical or electrical rooms in design and content. Utility vaults are located underground for aesthetic, safety, and security reasons. Typically, utility delivery networks include a series of main lines connected to branch lines that provide utility connections to individual houses and apartments. There could be a utility vault located at every junction between main lines and every junction between main line and branch line and at every junction between branch lines. Utility vaults are required with most sewer and drainage storage tanks, flow junctions, pump houses, and other areas of the sewage and drainage system of a village, municipality, town, city, or county. Thus, a typical utility distribution network or system includes a large number of utility vaults. Utility vaults are commonly constructed out of reinforced concrete boxes, poured cement, or brick. Utility vaults are typically entered through a manhole or vault cover on the upper surface or ceiling of the utility vault. Utility vault covers are used to prevent accidental and unauthorized access to a utility vault. Utility vault covers typically have latching and/or locking mechanisms to prevent unauthorized access to the utility vault.
A utility vault is typically a rectangular or square cuboid or box-shaped room. The utility vault cover is typically on the upper face of the cuboid. A utility vault cover is typically rectangle or square-shaped. A utility vault cover is pivotally attached at one end to the upper face of the cuboid. A utility vault cover is typically rotated upwards to open the cover and gain access to the utility vault and pivotally rotated downwards to close the cover and eliminate access to the utility vault.
A utility vault cover typically comprises a frame and a hatch. The frame is a closed-perimetered rigid assembly with an open center that is typically rectangular-shaped or square-shaped to fit the specific cuboid dimensions of the utility vault. The frame is attached to the utility vault on the upper face or at the upper edges of the vertical faces of the cuboid. The frame and utility vault are typically embedded into the ground with the upper surface of the frame generally flush with the upper surface of the ground of the surrounding area, which is typically earth, concrete, asphalt, or similar.
The hatch is a rigid planer member sized to fit and cover the upper face of the cuboid-shaped utility vault and to marry with the frame to make a semi-weather-tight connection with the frame. The hatch is typically square or rectangular shaped. One edge of the hatch is pivotally mounted on one leg of the frame so that the edge of the hatch opposite the pivotally mounted edge may be lifted upwards to open the hatch and pushed downwards to close the hatch.
Traffic-rated utility vault covers must be sturdy enough to support the continuous flow vehicular traffic and/or pedestrian traffic passing overtop without losing structural integrity, deflecting, bending, vibrating, or moving in any way. A traffic-rated utility vault cover must be of a very heavy-duty design to support the enormous amounts of weight and large volumes of people, cars, and trucks passing over the utility vault. In addition, the cover must form a semi-weather-tight connection with the frame to help keep the interior of the utility vault dry and safe from sun, wind, rain, ice, snow, insects, rodents, and the like. To accomplish this, a latching mechanism or closing mechanism is required to securely hold down the hatch and to form a semi-weather-tight connection with the frame while also supporting the enormous amounts of weight and stress from the hatch and the traffic passing over it.
For safety reasons, a closed, latched, and/or locked hatch should not open, shift, deflect, deform, bend, vibrate, or move in any way because this would pose a very serious safety problem to people and vehicles attempting to pass over the utility vault as they could fall in the utility vault or otherwise hurt themselves or damage their property if the hatch is jostled while they pass overtop. Further, even small vibrations of the hatch or its latching and/or locking mechanisms over extended periods can lead to latch and/or lock failure causing the same safety issues. Small vibrations between the hatch and frame of a utility vault cover can cause the hatch to open, shift, deflect, deform, bend, vibrate, or move.
To remedy this, applicant has devised a heavy-duty stationary self-draining fastening post with vibration-free frame attachment that together with a bolt or other fastener will securely hold down the hatch to the frame to yield a strong, rigid, vibration-free connection between these members that is capable of supporting enormous amounts of weight without losing structural integrity, deflecting, bending, vibrating, or moving in any way.
In the prior art, there are a few mechanisms or systems designed to hold down and secure manhole covers located on streets or sidewalks or other traffic areas. Most prior art mechanisms secure the manhole cover with a plurality of bolt members or threaded stud members, each passing through a clearance hole in the manhole cover and threaded into a floating nut member or similar floating tapped hole member on the other side. The nut member is “floating” because it must be able to track along the bolt member as the bolt member is rotated to loosen or tighten the connection. Typically, floating nut members are secured to the frame-side to provide crews access to the heads of the bolt members on the topside of the manhole cover. When a bolt member is tightened, the floating nut member tracks along the bolt member until it is limited by its frame-side attachment to start to squeeze the manhole cover between the bolt member head and the floating washer member. Tightening the bolt beyond the limit point pushes the manhole cover down to clamp onto the frame of the structure. The bolt members pull down on the manhole cover to hold the manhole cover down onto the frame, which is stationary in the ground. Most prior art mechanisms secure manhole covers using the floating nut member design.
The floating nut member design is inferior because nut members are floating or moving members, which prompts a smaller, less robust design. Nut members must track up and down to a certain extent relative to bolt members as the bolt members are turned by utility crews to open or close the hatch. This design leads to a less robust nut member design because nut members must be sized smaller than the bolt members so that nut members can track along the bolt members. This leads to a smaller amount of threads on the bolt member actually engaged with and in physical contact with female threads on the nut member. Less thread contact between these members means a less clamping pressure exerted to hold the hatch down onto the frame. Less clamping pressure here means a less sturdy design that is more prone to deflecting, bending, vibrating, or moving from heavy traffic passing overtop.
Also, the floating nature itself of the floating nut member is an inferior design because the floating nut moves. Floating nut member is not rigidly attached to the frame and is thereby much more susceptible to vibrations. A moving anchor point is less capable of holding a strong rigid vibration-free connection between the hatch and frame of a traffic-rated utility vault cover. The floating nut member design is less sturdy and allows more of a likelihood that the hatch would open, shift, move, deflect, bend, or vibrate from heavy traffic passing overtop.
This invention includes a massive stationary nut member design where the nut member is an oblong heavy mass with a deep tapped hole where at least one inch of thread in the tapped hole in the nut member engages and physically contacts threads on the bolt members to yield a much more robust design capable of delivering huge amounts of clamping pressure to securely hold down the hatch to the frame and support enormous amounts of weight passing overtop without bending, deflecting, vibrating, or moving in any way. Massive stationary nut members are attached to the frame with a strong, rigid, vibration-free connection including a closed-loop continuous singular full-perimeter weld around each nut member without any holes or structural voids in the frame near the vicinity of the weld. The design of this invention is a substantial improvement over all floating washer member designs.
A drawback to the massive stationary nut member design is that the tapped hole of the nut member is susceptible to debris build-up because the tapped hole stands upright and massive stationary nut member cannot be easily moved or removed for cleaning. Further, once the tapped-hole of the nut member is clogged with debris, it is practically impossible to completely clean out because flushing the upright blind hole does not completely remove all debris. This is a problem because a large amount of debris can build-up in the tapped hole causing back pressure on the bolt member to prevent the proper clamping pressure on the hatch. To remedy this, this invention includes a novel method of preventing debris build-up in the heavy-duty stationary self-draining fastening post with the use of a special drainage port.